Selection by compartmentalised screening

Abstract

The invention describes a method for the identification of compounds which bind to a target component of a biochemical system or modulate the activity of the target, comprising the steps of: a.) compartmentalizing the compounds into microcapsules together with the target, such that only a subset of the repertoire is represented in multiple copies in any one microcapsules; and b.) identifying the compound which binds to or modulates the activity of the target. The invention enables the screening of large repertoires of molecules which can serve as leads for drug development.

The invention claimed is: 
     
       1. A method for screening compounds, the method comprising:
 introducing a first aqueous fluid comprising a target enzyme and a second aqueous fluid comprising a repertoire of small molecule compounds by separately injecting the first aqueous fluid and the second aqueous fluid into an immiscible fluorocarbon oil continuously flowing through a first microfluidic channel to form a plurality of first water-in-fluorocarbon oil microcapsules, wherein the first immiscible fluorocarbon oil comprises a fluorosurfactant, and wherein each aqueous portion of each of the plurality of the first water-in-fluorocarbon oil microcapsule comprises the target enzyme and a subset of the repertoire of small molecule compounds; 
 continuously flowing the plurality of the first water-in-fluorocarbon oil microcapsules through the first microfluidic channel and conducting a first target enzyme catalyzed reaction between the target enzyme and the subset of the repertoire of small molecule compounds within the aqueous portion of each of the plurality of the first water-in-fluorocarbon oil microcapsules to produce a first reaction product; 
 introducing a third aqueous fluid comprising a fluorogenic substrate from a second microfluidic channel, wherein the fluorogenic substrate is specific for the target enzyme; 
 merging a plurality of second water-in-fluorocarbon oil microcapsules flowing through the second microfluidic channel with the plurality of the first water-in-fluorocarbon oil microcapsules flowing through the first microfluidic channel to form a plurality of merged water-in-fluorocarbon oil microcapsules, wherein the aqueous portion of each of the plurality of second water-in-fluorocarbon oil microcapsules comprises the fluorogenic substrate, to form a plurality of merged water-in-fluorocarbon oil microcapsules, wherein the aqueous portion of the plurality of merged water-in-fluorocarbon oil microcapsules comprises the first reaction product and the fluorogenic substrate; 
 conducting a second enzyme catalyzed reaction between the first reaction product and the fluorogenic substrate within the aqueous portion of each of the plurality of the merged water-in-fluorocarbon oil microcapsules to produce a second reaction product; and 
 optically detecting the second reaction product. 
 
     
     
       2. The method according to  claim 1 , wherein optically detecting is fluorescently detecting. 
     
     
       3. The method according to  claim 1 , further comprising attaching a small molecule compound to a microbead. 
     
     
       4. The method according to  claim 3 , wherein attaching occurs prior to introducing the first aqueous liquid and the second aqueous liquid into the immiscible fluorocarbon oil. 
     
     
       5. The method according to  claim 3 , wherein attaching occurs after introducing the first aqueous liquid and the second aqueous liquid into the immiscible fluorocarbon oil and before conducting the first target enzyme catalyzed reaction. 
     
     
       6. The method according to  claim 3 , wherein the small molecule compound is covalently attached to the microbead. 
     
     
       7. The method according to  claim 3 , wherein the small molecule compound is non-covalently attached to the microbead. 
     
     
       8. The method according to  claim 6 , wherein the small molecule compound is attached to the microbead through a cleavable linker. 
     
     
       9. The method according to  claim 1 , wherein the surfactant is of the formula C 8 F 17 C 11 H 22 OP(O)[N(CH 2 CH 2 ) 2 O] 2 . 
     
     
       10. The method according to  claim 1 , wherein each of the plurality of the first water-in-fluorocarbon oil microcapsules comprises multiple copies of a single small molecule compound. 
     
     
       11. The method according to  claim 1 , wherein the first aqueous fluid further comprises a plurality of cells and each of the plurality of the first water-in-fluorocarbon oil microcapsules comprises a cell. 
     
     
       12. The method according to  claim 11 , wherein the target enzyme in each of the plurality of the first water-in-fluorocarbon oil microcapsules is part of the cell. 
     
     
       13. The method according to  claim 11 , wherein the target enzyme in each of the plurality of the first water-in-fluorocarbon oil microcapsules is in the cell. 
     
     
       14. The method of  claim 1 , wherein the fluorocarbon oil is perfluorocarbon. 
     
     
       15. The method of  claim 14 , wherein at least one small molecule compound activates the activity of the enzyme. 
     
     
       16. The method of  claim 14 , wherein at least one small molecule compound inhibits the activity of the enzyme. 
     
     
       17. The method of  claim 1 , wherein the repertoire of small molecule compounds comprises at least 100 different compounds.